Polyesters, such as poly(ethylene terephthalate) or PET, and poly(butylene terephthalate) or PBT, are widely used in the preparation of articles by forming methods such as injection molding and tube extrusion. Many of their properties, including chemical stability, solvent resistance and low permeability to gases, make them attractive candidates for such forming operations as blow molding, profile extrusion and thermoforming.
Additionally, polyester resins modified with linear amines have found use in various commercial applications. For example, Marcus, U.S. Pat. No. 3,886,230, teaches that dyeable polyesters can be prepared by blending conventional polyesters with modified polyesters containing a di(hydroxyalkyl)amine polymerized in the molecule. Pacifici et al., U.S. Pat. No. 4,374,716, teach the use of polyesters prepared from glycols containing a linear tertiary amine in UV curable compositions.
However, none of the prior art references teach or suggest a polyester resin having free amine functionality in the polymer. The prior art references teach only the reaction of polyesters with linear amines which provides a polymer having amide linkages. Surprisingly, it has now been found that polyesters having free aromatic amine functionality can be provided by reacting the polyester with an aromatic amine acid, ester or alcohol.